The cubic equation on a graph

The curve again, with its solution marked. Where $y=0$, the curve is on the $\displaystyle x$-axis: only once, at the real solution, $\displaystyle -1.23$. Where $y<0$, the curve is below the axis: to the left of the solution. Where $y>0$, it is above the axis: to the right. The two Complex do not appear on the graph: the curve meets the axis only once.